Braking systems have been proposed wherein the brakes can be electrically controlled from a solenoid operated valve connected in series with the usual "emergency" brake control which mechanically actuates a valve by pushing or pulling a plunger located on the vehicle dashboard. The electrically operated valve may be operated from the transmission control console, so that a "park" position may be selected which results in the transmission being shifted to neutral and the emergency brakes being applied. The electrically operated valve is usually spring biased to a position applying the brakes when the solenoid is deenergized. In order to release the brakes the solenoid must be energized from the vehicle battery. One of the problems with such systems is that an unexpected loss of electrical power results in de-energization of the electrically operated valve and application of the brakes which may create a hazardous condition.